Resonant sonic cleaning utilizing particulate material in conjunction with a sonic reflective baffle member

ABSTRACT

A PART TO BE CLEANED IS SUSPENDED IN A PARTICULATE MEDIUM. THE GRANULES OF THE PARTICULATE MATERIAL ARE RANDOMLY VIBRATED BY MEANS OF A RESONANT VIBRATION SYSTEM, THE OUTPUT OF WHICH IS COUPLED TO SUCH MATERIAL THROUGH A VIBRATIONAL MEMBER SUCH AS A DIAPHRAGM. A SONIC REFLECTIVE BAFFLE MEMBER IS SUPPORTED IN THE MIDST OF THE GRANULAR MEDIUM OPPOSITE THE DIAPHRAGM WITH THE PART TO BE CLEANED LOCATED BETWEEN THE BAFFLE AND DIAPHRAGM. THE BAFFLE FUNCTIONS TO CONCENTRATE THE ACOUSTICAL ENERGY SO AS TO CAUSE A STREAMING OF THE PARTICULATE MATERIAL IN THE REGION ADJACENT TO THE PART. SUCH ENERGY WORKS ON ALL SIDES OF THE PART TO PROVIDE HIGHLY EFFECTIVE CLEANING AND FINISHING ACTION THEREON.

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/l//ll/ Feb. 23, 1971 RESONANI SONIC CLEANING UTILIZING PARTICULATEMATERIAL IN CONJUNCTION WITH A SONIC REFLECTIVE BAFFLE MEMBER Filed Feb.l0, 1969 BODINE l [lll INVENTOR.

United States Patent O 3,564,775 RESONANT SONIC CLEANING UTILIZING PAR-TICULATE MATERIAL IN CONJUNCTION WITH A SONIC REFLECTIVE BAFFLE MEMBERAlbert G. Bodne, 7877 Woodley Ave., Van Nuys, Calif. 91406 Filed Feb.10, 1969, Ser.y No. 797,751 Int. Cl. B24b 1 9/ 00 U.S. Cl. 51--7 4Claims ABSTRACT OF THE DISCLOSURE A part to be cleaned is suspended in aparticulate medium. The granules of the particulate material arerandomly vibrated by means of a resonant vi-bration system, the outputof which is coupled to such material through a vibrational member suchas a diaphragm. A sonic reflective baffle member is supported in themidst of the granular medium opposite the diaphragm with the part to becleaned located between the baffle and diaphragm. The baffle functionsto concentrate the acoustical energy so as to cause a streaming of theparticulate material in the region adjacent to the part. Such energyworks on all sides of the part to provide highly effective cleaning andfinishing action thereon.

This invention relates to the cleaning and polishing of mechanical partsand more particularly to the utilization of sonic energy to achieve suchend results.

In my Pat. No. 3,380,195, issued Apr. 30, 1968, apparatus is describedfor effectively cleaning and finishing mechanical parts by placing suchparts in a container of granular material and then resonantly vibratingthe part to be cleaned, thereby effecting the cleaning action.

It has been found that a marked improvement in the cleaning action canbe obtained by randomly vibrating the particles of the particulatematerial as a load on a resonant vibration system and by placing areflective baffle in the particulate material. The part is locatedbetween this baffle and a vibratory member such as a diaphragm throughwhich the resonant energy is coupled to the material. This effectivelyconcentrates the resonant energy in the immediate region of the part andcauses an effective streaming of the particulate material around thepart in a manner akin to a lboiling action so as to greatly enhance thecleaning action.

It is therefore the principle of each object of this invention toimprove the cleaning action of sonically vibrated particulate materialby providing a reflective baffle in such material to concentrate thesonic energy in a stream which flows around the surfaces of the part tobe cleaned.

Other objects of the invention will become apparent as the descriptionproceeds in connection with the accompanying drawings, of which:

FIG. 1 is an elevational view in cross-section of a first embodiment ofthe device of the invention; and

FIG. 2 is an elevational Iview in cross-section of the second embodimentof the device of the invention.

It has been found most helpful in analyzing the device of this inventionto analogize the acoustically vibrating circuit utilized to anequivalent electrical circuit. Ths sort of approach to analysis is wellknown to those skilled in the art and is described, for example, inchapter 2 of Sonics by Hueter and Bolt, published in 1955 by John Wileyand Sons. In making such an analogy, force F is equated with electricalvoltage E, velocity of vibration u is equated with electrical current i,mechanical compliance Cm is equated with electrical capacitance Ce, massM is equated with electrical indnctance L,

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mechanical resistance (friction) Rm is equated with electricalresistance R and mechanical impedance Z,n is equated with electricalimpedance Ze.

Thus, it can be shown that if a member is elastically viIbr-ated bymeans of an acoustical sinusoidal force F0 sin wt (w being equal to 21rtimes the frequency of vibration), that 1 F0 sin wt zm-RMLJ (aM-wam)- u(l) Where wM is equal to l/wCm, a resonant condition exists, and theeffective mechanical impedance Zm is equal to the mechanical resistanceRm, the reactive impedance components wM and l/wCm cancelling each otherout. Under such la resonant condition, velocity of vibration u is at amaximum, power factor is unity, and energy is more efficiently deliveredto a load to which the resonant system may be coupled.

It is important to note the significance of the attainment of highacoustical Q in the resonant system being driven, to increase theefciency of the vibration thereof and to provide a maximum amount ofpower. As for an equivalent electrical circuit, the Q of an acousticallyvibrating circuit is defined as the sharpness of resonance thereof andis indicative of the ratio of the energy stored in each vibration cycleto the energy used in each such cycle. Q is mathematically equated tothe ratio between wM and Rm. Thus, the effective Q of the vibratingcircuit can be maximized to make for highly efficient, highamplitudevibration by minimizing the effect of friction in the circuit and/ormaximizing the effect of mass in such circuit.

In considering the significance of the parameters described inconnection with Equation 1, it should be kept in mind that the totaleffective resistance, mass, and compliance in the acoustically vibratingcircuit are represented in the equation and that these parameters may bedistributed throughout the system rather than being lumped in any onecomponent or portion thereof.

It is also to be noted that orbiting-mass oscillators are utilized inthe implementation of the invention that automatically adjust theiroutput frequency and phase to maintain resonance with changes in thecharacteristics of the load. Thus, in the face of changes in theeffective mass and compliance presented by the load with changes in theconditions of the work material as it is sonically excited, the systemautomatically is maintained in optimum resonant operation by virtue ofthe lock-in characteristic of lapplicants unique orbiting-massoscillators. Furthermore in this connection the orbiting-mass oscillatorautomatically changes not only its frequency but its phase angle andtherefore its power factor with changes in the resistive impedance load,to assure optimum efciency of operation at all times. The vibrationaloutput from such orbiting-mass oscillators also tends to be constrainedby the resonator to be generated along a controlled predeterminedcoherent path to provide maximum output along a desired axis.

Briefly described, the device of the invention comprises a containermember having a granular material such as a `grit or a slurry containedtherein. One wall of the container has a diaphragm member therein whichpreferably communicates directly with the granular medium. A bafflemember is suspended within the granular material opposite the diaphragm.ln other words, the baffle is located Well within the body mass of the-granular material, so that the baffle is surrounded by the granularmaterial and its vibratory energy field. The parts to be cleaned aresuspended between the diaphragm and the baffle, in one embodimet of theinvention fbeing loosely placed in the granular material, and in anotherembodiment of the invention being suspended from the baffle member.Sonic energy is generated by means of an orbiting-mass oscillator andcoupled to a resonant vibration system including the diaphragm.Vibrational energy is coupled from the diaphragm to cause randomvibration of the granular medium, a substantial portion of such energybeing reilected by the baille member, thereby resulting in aconcentration of the sonic action on the parts to be cleaned.

Referring now to FIG. l, a rst embodiment of the device of the inventionis illustrated. Container member 11 has a grit material 12 containedtherein, such as for example, coarse sand. In some instances the grit isa slurry containing a liquid. Container 11 may be cylindrical with acover 13 at the top thereof and elastic diaphragm member 14 forming thebottom thereof. Diaphragm 14 may be of suitable rubber or plasticmaterial. Baille member 15, which may be in the form of a circular platefabricated of a highly elastic material such as steel, is suspendedwithin granular medium 12 in a position directly opposite diaphragm 14by means of pillars 16 which extend upwardly from base plate 17. Baseplate 17 is ilxedly attached to diaphragm 14 by suitable means, such as,for example, cementing.

The part to be cleaned (18) is held between diaphragm 14 and baille 15in granular medium 12 by means of clamp 19, which is ilxedly attached tobaille 15.

I-Iigh-level sonic energy is provided to diaphragm 14 by means oforbiting-mass oscillator 21, the casing of which is coupled to thediaphragm through pneumatic springs formed by air-illled expansiblebladders 23 and 24, bladder 23 being coupled to the diaphragm throughplate 27.

Orbiting-mass oscillator 21 is rotatably driven by means of a motor (notshown) Iwhich is coupled to the oscillator through gear box 30 and driveshaft 3'1. The rotor of orbiting-mass oscillator 21 is driven at a speedsuch as to cause resonant elastic vibration of the vibration systemincluding pneumatic springs 23 and 24, plate member 27, diaphragm 14 andbaille 15.

The pneumatic spring mechanism, including bladder members 23 and 24, asdriven by oscillator 21, may be of the type described in connection withFIGS. 1 and 2 of my Pat. No. 3,406,782, issued Oct. 22, 1968. Thepneumatic spring device, as fully described in this patent, acts as animpedance transformer to assure optimum coupling of sonic energy to theload provided by the granular medium.

With the orbiting-mass oscillator 21 adjusted to a frequency to causeresonant elastic vibration of the vibration system, including diaphragm14 and baille 15, the granular material 12 is caused to randomly vibrateat a high energy level, such vibration being concentrated on part 18.The granular material tends to boil or stream around the part toeffectively clean all the surfaces thereof, the energy beingconcentrated in the area of the part in a zone formed between thesubmerged bafile and the diaphragm. The baille causes a vibratory energygradient within the body of granular material. There thus is a very highenergy level flow of the particulate material in the slot formed betweenthe baille and the diaphragm. It is to be noted that in this embodimentof the invention that the diaphragm and baille vibrate together inresponse to the sonic energy.

Referring now to FIG. 2, a second embodiment of the device of theinvention is illustrated. For this embodiment, for the convenience ofillustration, the oscillator and pneumatic diaphragm Imechanism are notshown as they may be the same as that illustrated in FIG. l and justdescribed in connection therewith. In this second embodiment, container11 is similar to that described for the ilrst embodiment and containsgranular material 12 therein. In this second embodiment, however, ratherthan the. parts being iixed in position and suspended from the baille,parts 35 are rather placed in the granular material between baille 15and diaphragm 14. Batlle 15 is suspended in the granular medium from thetop cover 13 of the container member by means of arms 37. In thisembodiment thus, baille 15 is not included in the resonant vibrationalsystem and merely acts to reilect sonic energy received thereby throughthe granular medium. As for the iirst embodiment diaphragm 14 isvibrated as part of a resonant vibration system and causes highlevelrandom Vibration through the particles of granular medium 12, theseparticles being caused to boil or ilow through the area bounded bybaille member 15 and diaphragm 14.

The device of this invention thus provides highly effective means forconcentrating sonic random vibration of particulate material in theregion in which parts to be cleaned are located. The sonic activity ofthe particulate material is enhanced by a streaming action of suchmaterial in response to the sonic energy such as to effectively providecleaning action to all of the surfaces of the parts to be Cleaned.

I claim:

1. Apparatus for cleaning parts, comprising:

a container member;

particulate material contained within said container member;

a vibratory diaphragm member located in one of the walls of saidcontainer member, and in direct communication with said particulatematerial;

a baille member suspended in said particulate material opposite saiddiaphragm,

the part to be cleaned being suspended in said particulate materialbetween said baille and said diaphragm;

a resonant vibration system, said system including said diaphragm; and

an orbiting-mass oscillator, the output of said orbitingmass oscillatorbeing coupled to said resonant vibration system;

said orbiting-mass oscillator being driven at a frequency such as tocause resonant elastic vibration of said vibration system,

whereby the individual particles of said material are caused to vibraterandomly to provide a streaming of said particulate material in the areasurrounding said part.

2. The apparatus of claim 1 wherein said part is suspended from saidbaille member, said baille member being supported on said diaphragm andvibrating therewith.

3. The device of claim 1 wherein said baille member is suspended in saidparticulate material from said container.

4. The device of claim 3 wherein said part is loosely suspended in theparticulate material between said bafile and said diaphragm.

References Cited UNITED STATES PATENTS JAMES L, JONES, J R., PrimaryExaminer

